Elasticsearch filter plugin

• Plugin version: v4.0.0
• Released on: 2025-01-10
• Changelog

For other versions, see the Versioned plugin docs.

For questions about the plugin, open a topic in the Discuss forums. For bugs or feature requests, open an issue in Github. For the list of Elastic supported plugins, please consult the Elastic Support Matrix.

Search Elasticsearch for a previous log event and copy some fields from it into the current event. Below are two complete examples of how this filter might be used.

The first example uses the legacy query parameter where the user is limited to an Elasticsearch query_string. Whenever logstash receives an "end" event, it uses this elasticsearch filter to find the matching "start" event based on some operation identifier. Then it copies the @timestamp field from the "start" event into a new field on the "end" event. Finally, using a combination of the "date" filter and the "ruby" filter, we calculate the time duration in hours between the two events.

if [type] == "end" {
   elasticsearch {
      hosts => ["es-server"]
      query => "type:start AND operation:%{[opid]}"
      fields => { "@timestamp" => "started" }
   }

   date {
      match => ["[started]", "ISO8601"]
      target => "[started]"
   }

   ruby {
      code => "event.set('duration_hrs', (event.get('@timestamp') - event.get('started')) / 3600)"
   }
}

The example below reproduces the above example but utilises the query_template. This query_template represents a full Elasticsearch query DSL and supports the standard Logstash field substitution syntax. The example below issues the same query as the first example but uses the template shown.

if [type] == "end" {
      elasticsearch {
         hosts => ["es-server"]
         query_template => "template.json"
         fields => { "@timestamp" => "started" }
      }

      date {
         match => ["[started]", "ISO8601"]
         target => "[started]"
      }

      ruby {
         code => "event.set('duration_hrs', (event.get('@timestamp') - event.get('started')) / 3600)"
      }
}

template.json:

{
  "size": 1,
  "sort" : [ { "@timestamp" : "desc" } ],
  "query": {
    "query_string": {
      "query": "type:start AND operation:%{[opid]}"
    }
  },
  "_source": ["@timestamp"]
}

As illustrated above, through the use of opid, fields from the Logstash events can be referenced within the template. The template will be populated per event prior to being used to query Elasticsearch.

Notice also that when you use query_template, the Logstash attributes result_size and sort will be ignored. They should be specified directly in the JSON template, as shown in the example above.

Authentication to a secure Elasticsearch cluster is possible using one of the following options:

• user AND password
• cloud_auth
• api_key
• ssl_keystore_path and/or ssl_keystore_password

Authorization to a secure Elasticsearch cluster requires read permission at index level and monitoring permissions at cluster level. The monitoring permission at cluster level is necessary to perform periodic connectivity checks.

This plugin supports the following configuration options plus the Common options described later.

Also see Common options for a list of options supported by all filter plugins.

• Value type is hash
• Default value is {}

Hash of aggregation names to copy from elasticsearch response into Logstash event fields

Example:

filter {
  elasticsearch {
    aggregation_fields => {
      "my_agg_name" => "my_ls_field"
    }
  }
}

• Value type is password
• There is no default value for this setting.

Authenticate using Elasticsearch API key. Note that this option also requires enabling the ssl_enabled option.

Format is id:api_key where id and api_key are as returned by the Elasticsearch Create API key API.

• Value type is string, and must contain exactly 64 hexadecimal characters.
• There is no default value for this setting.
• Use of this option requires Logstash 8.3+

The SHA-256 fingerprint of an SSL Certificate Authority to trust, such as the autogenerated self-signed CA for an Elasticsearch cluster.

• Value type is password
• There is no default value for this setting.

Cloud authentication string ("<username>:<password>" format) is an alternative for the user/password pair.

For more info, check out the Logstash-to-Cloud documentation.

• Value type is string
• There is no default value for this setting.

Cloud ID, from the Elastic Cloud web console. If set hosts should not be used.

For more info, check out the Logstash-to-Cloud documentation.

• Value type is hash
• Default value is {}

Hash of docinfo fields to copy from old event (found via elasticsearch) into new event

Example:

filter {
  elasticsearch {
    docinfo_fields => {
      "_id" => "document_id"
      "_index" => "document_index"
    }
  }
}

• Value type is boolean
• Default value is true

Whether results should be sorted or not

• Value type is array
• Default value is {}

An array of fields to copy from the old event (found via elasticsearch) into the new event, currently being processed.

In the following example, the values of @timestamp and event_id on the event found via elasticsearch are copied to the current event’s started and start_id fields, respectively:

fields => {
  "@timestamp" => "started"
  "event_id" => "start_id"
}

• Value type is array
• Default value is ["localhost:9200"]

List of elasticsearch hosts to use for querying.

• Value type is string
• Default value is ""

Comma-delimited list of index names to search; use _all or empty string to perform the operation on all indices. Field substitution (e.g. index-name-%{{date_field}}) is available

• Value type is password
• There is no default value for this setting.

Basic Auth - password

• Value type is uri
• There is no default value for this setting.

Set the address of a forward HTTP proxy. An empty string is treated as if proxy was not set, and is useful when using environment variables e.g. proxy => '${LS_PROXY:}'.

• Value type is string
• There is no default value for this setting.

Elasticsearch query string. More information is available in the Elasticsearch query string documentation. Use either query or query_template.

• Value type is string
• There is no default value for this setting.

File path to elasticsearch query in DSL format. More information is available in the Elasticsearch query documentation. Use either query or query_template.

• Value type is number
• Default value is 1

How many results to return

• Value type is number
• Default value is 0 (retries disabled)

How many times to retry an individual failed request.

When enabled, retry requests that result in connection errors or an HTTP status code included in retry_on_status

• Value type is array
• Default value is an empty list []

Which HTTP Status codes to consider for retries (in addition to connection errors) when using retry_on_failure,

• Value type is string
• Default value is "@timestamp:desc"

Comma-delimited list of <field>:<direction> pairs that define the sort order

• Value type is path
• There is no default value for this setting.

SSL certificate to use to authenticate the client. This certificate should be an OpenSSL-style X.509 certificate file.

• Value type is a list of path
• There is no default value for this setting

The .cer or .pem files to validate the server’s certificate.

• Value type is a list of string
• There is no default value for this setting

The list of cipher suites to use, listed by priorities. Supported cipher suites vary depending on the Java and protocol versions.

• Value type is boolean
• There is no default value for this setting.

Enable SSL/TLS secured communication to Elasticsearch cluster. Leaving this unspecified will use whatever scheme is specified in the URLs listed in hosts or extracted from the cloud_id. If no explicit protocol is specified plain HTTP will be used.

• Value type is path
• There is no default value for this setting.

OpenSSL-style RSA private key that corresponds to the ssl_certificate.

• Value type is password
• There is no default value for this setting.

Set the keystore password

• Value type is path
• There is no default value for this setting.

The keystore used to present a certificate to the server. It can be either .jks or .p12

• Value can be any of: jks, pkcs12
• If not provided, the value will be inferred from the keystore filename.

The format of the keystore file. It must be either jks or pkcs12.

• Value type is string
• Allowed values are: 'TLSv1.1', 'TLSv1.2', 'TLSv1.3'
• Default depends on the JDK being used. With up-to-date Logstash, the default is ['TLSv1.2', 'TLSv1.3']. 'TLSv1.1' is not considered secure and is only provided for legacy applications.

List of allowed SSL/TLS versions to use when establishing a connection to the Elasticsearch cluster.

For Java 8 'TLSv1.3' is supported only since 8u262 (AdoptOpenJDK), but requires that you set the LS_JAVA_OPTS="-Djdk.tls.client.protocols=TLSv1.3" system property in Logstash.

• Value type is password
• There is no default value for this setting.

Set the truststore password

• Value type is path
• There is no default value for this setting.

The truststore to validate the server’s certificate. It can be either .jks or .p12.

• Value can be any of: jks, pkcs12
• If not provided, the value will be inferred from the truststore filename.

The format of the truststore file. It must be either jks or pkcs12.

• Value can be any of: full, none
• Default value is full

Defines how to verify the certificates presented by another party in the TLS connection:

full validates that the server certificate has an issue date that’s within the not_before and not_after dates; chains to a trusted Certificate Authority (CA), and has a hostname or IP address that matches the names within the certificate.

none performs no certificate validation.

• Value type is array
• Default value is ["_elasticsearch_lookup_failure"]

Tags the event on failure to look up previous log event information. This can be used in later analysis.

• Value type is string
• There is no default value for this setting.

Basic Auth - username

These configuration options are supported by all filter plugins:

• Value type is hash
• Default value is {}

If this filter is successful, add any arbitrary fields to this event. Field names can be dynamic and include parts of the event using the %{{field}}.

Example:

filter {
  elasticsearch {
    add_field => { "foo_%{somefield}" => "Hello world, from %{host}" }
  }
}

# You can also add multiple fields at once:
filter {
  elasticsearch {
    add_field => {
      "foo_%{somefield}" => "Hello world, from %{host}"
      "new_field" => "new_static_value"
    }
  }
}

If the event has field "somefield" == "hello" this filter, on success, would add field foo_hello if it is present, with the value above and the %{{host}} piece replaced with that value from the event. The second example would also add a hardcoded field.

• Value type is array
• Default value is []

If this filter is successful, add arbitrary tags to the event. Tags can be dynamic and include parts of the event using the %{{field}} syntax.

Example:

filter {
  elasticsearch {
    add_tag => [ "foo_%{somefield}" ]
  }
}

# You can also add multiple tags at once:
filter {
  elasticsearch {
    add_tag => [ "foo_%{somefield}", "taggedy_tag"]
  }
}

If the event has field "somefield" == "hello" this filter, on success, would add a tag foo_hello (and the second example would of course add a taggedy_tag tag).

• Value type is boolean
• Default value is true

Disable or enable metric logging for this specific plugin instance. By default we record all the metrics we can, but you can disable metrics collection for a specific plugin.

• Value type is string
• There is no default value for this setting.

Add a unique ID to the plugin configuration. If no ID is specified, Logstash will generate one. It is strongly recommended to set this ID in your configuration. This is particularly useful when you have two or more plugins of the same type, for example, if you have 2 elasticsearch filters. Adding a named ID in this case will help in monitoring Logstash when using the monitoring APIs.

filter {
  elasticsearch {
    id => "ABC"
  }
}

• Value type is boolean
• Default value is false

Call the filter flush method at regular interval. Optional.

• Value type is array
• Default value is []

If this filter is successful, remove arbitrary fields from this event. Fields names can be dynamic and include parts of the event using the %{{field}} Example:

filter {
  elasticsearch {
    remove_field => [ "foo_%{somefield}" ]
  }
}

# You can also remove multiple fields at once:
filter {
  elasticsearch {
    remove_field => [ "foo_%{somefield}", "my_extraneous_field" ]
  }
}

If the event has field "somefield" == "hello" this filter, on success, would remove the field with name foo_hello if it is present. The second example would remove an additional, non-dynamic field.

• Value type is array
• Default value is []

If this filter is successful, remove arbitrary tags from the event. Tags can be dynamic and include parts of the event using the %{{field}} syntax.

Example:

filter {
  elasticsearch {
    remove_tag => [ "foo_%{somefield}" ]
  }
}

# You can also remove multiple tags at once:
filter {
  elasticsearch {
    remove_tag => [ "foo_%{somefield}", "sad_unwanted_tag"]
  }
}

If the event has field "somefield" == "hello" this filter, on success, would remove the tag foo_hello if it is present. The second example would remove a sad, unwanted tag as well.